Mitutoyo 530-312 Vernier Calipers, Stainless Steel, for Inside, Outside, Depth and Step Measurements, Metric, 0"/0mm-150mm Range, +/-0.03mm Accuracy, 0.02mm Resolution, 40mm Jaw Depth Hardened stainless steel construction with satin chrome finish, for protection of caliper Four-way measurement capability for outside dimension (OD), inside dimension (ID), depth, and step measurements Raised sliding surfaces to help prevent defacement and wear of scale graduations Modest, 14-degree face angle on vernier scale, to help improve visibility and reduce the possibility of parallax errors Meets Federal Accuracy Specifications GGG-C-111B